Interesting case of a man detained at an airport because authorities couldn’t fingerprint him.

According to MedPage Today, he was taking the chemotherapy drug capecitabine which causes so-called hand-foot syndrome, or palmar-plantar erythrodysesthesia. The chronic inflammation causes the skin on the hands to peel and blister, which can eventually eradicate a patient’s fingerprints.

In a study looking at the drug, this type of inflammation occurs in about 65 percent of patients taking the drug, although this degree of severity happens in only 5 percent of cases.

Patients on this medication should carry a note from their oncologist if they plan to travel internationally.